Miniaturization of CMOS devices has led to improved performance of a signal processing device. The device, as a logic processing unit, has contributed to higher functions and higher performances of products in various markets. It is expected, however, that the miniaturization, which has been promoted so far by solving a multitude of manufacturing problems, will eventually reach the physical limit. In addition, along with the miniaturization, power consumption of the devices has become a major problem. Dynamic power increasing with the miniaturization has been controlled, resulting in increased static power. This has led to skyrocketing power consumption along with the miniaturization.
Under these circumstances, various approaches are underway as a breakthrough towards further improvements of performances. One of the approaches is to construct a signal processing device which is based on non-Boolean algebra logic and specialized in particular processing. In particular, a processing technique called Morcphic architecture encompasses neurocomputing, cellular nonlinear network, or the like, and excels at signal processing such as learning and pattern recognition, which CMOSs do not well. Such devices employ multi-input one-output signal processing as a basic unit of calculation, and the signal processing is based on multi-input addition. Accordingly, a structure of those signal processing devices is expected to widely differ from a conventional MOSFET structure having a signal ON/OFF function which is suited for sequential Boolean algebraic manipulation aimed at general logical manipulation.
Meanwhile, with respect to materials, information processing is being considered which uses light, spin or biotechnology or the like having degrees of freedom different from those of electric charge conventionally utilized. A spin MOSFET, a Datta-Das type spin transistor, a spin gain transistor and the like have been proposed as an information processing device using a spin. Many of these devices have an FET transistor structure and are suited for Boolean algebra operation. A transistor using a spin wave is also proposed (see, for example, USPA20070296516 or Appl. Phys. Lett. 87 (2005) 153501). Such a transistor is expected to be reduced in power consumption because it can be energized with small energy, in principle. However, since a spin wave is excited by a magnetic field generated from a transmission line structure in such devices, electricity needed for the excitation inevitably increases. In addition, the transmission line requires a large area, and thus does not have a structure suitable to be used as a multi-input electrode.